An electroluminescence test for a Concentrated PV system is presented with the objective of capturing high resolution pseudo-efficiency maps that highlight optical defects in the concentrator system. Key parameters of the experimental setup and imaging system are presented. Image processing is discussed, including comparison of experimental to nominal results and the quantitative estimation of optical efficiency. Efficiency estimates are validated using measurements under a collimated solar simulator and ray-tracing software. Further validation is performed by comparison of the electroluminescence technique to direct mapping of the optical efficiency. Initial results indicate the mean estimation error for Isc is -2.4% with a standard deviation is 6.9% and a combined measurement and analysis time of less than 5 seconds per optic. An extension of this approach to in-line quality control is discussed.